Method and apparatus for snow making

ABSTRACT

High velocity streams of compressed air and pressurized water are furnished in a cold ambient atmosphere from two independent sources of supply and precooled by momentarily confining the high velocity streams in elongated passageways formed in a snow-making jet construction whose outer surfaces are exposed to the cold ambient atmosphere. Portions of the passageways in the jet structure are arranged in a manner such that the stream of water is precooled by the cold ambient atmosphere and an inner stream of compressed air undergoes peripheral precooling by means of the precooled stream of pressurized water. The precooled stream of air may undergo successive stages of expansion while in a confined state to further cool the mixture. Regulated quantities of the precooled compressed air may also be injected into the confined stream of water at predetermined points thereby to control snow characteristics. Precooling compressed air and water with the jet construction of the invention produces snow at efficiency levels not heretofore realized in the art of snow making, and the characteristics of the snow crystals or particles being desirably controlled.

United States Patent [1 91 Tropeano et a1.

[45.] Sept. 25, 1973 METHOD AND APPARATUS FOR SNOW MAKING [76]Inventors: Joseph C. Tropeano, 20 Revere St.';

Philip L. Tropeano, 12 Revere St., both of Lexington, Mass.

[22] Filed: Feb. 17, 1972 [21] Appl. No.: 227,126

152 us. or. 239/2 s, 2.39/14 [51] lnt. C1. F25c 3/04 [58] Field ofSearch 239/2 S, 14

[56] References Cited UNITED STATES PATENTS 3,408,005 10/1968 Struble eta1. 239/2 S 3,010,660 11/1961 Barrett 239/2 S 3,298,612 1/1967 Torrens239/2 S 3,301,485 1/1967 Tropeano et a1. 239/14 X 3,464,625 9/1969Carlsson 239/2 S 3,596,476 8/1971 Jakob et a1. 239/2 S PrimaryExaminer-M. Henson Wood, Jr. Assistant Examiner-John J. LoveArt0rneyMunroe H. Hamilton [57] ABSTRACT High velocity streams ofcompressed air and pressurized water are furnished in a colclambientatmosphere from two independent sources of supply and precooledby momentarily confining the high velocity streams in elongatedpassageways formed in a snow-making jet construction whose outersurfaces are exposed to the cold ambient atmosphere. Portions of thepassageways in the jet structure are arranged in a manner such that thestream of water is precooled by the cold ambient atmosphere and an innerstream of compressed air undergoes peripheral precooling by means of theprecooled stream of pressurized water. The precooled stream of air mayundergo successive stages of expansion while in a confined state tofurther cool the mixture. Regulated quantities of the precooledcompressed air may also be injected into the confined stream of art ofsnow making, and the characteristics of the snow crystals or particlesbeing desirably controlled.

3 Claims, 8 Drawing Figures PATENTEDSEP25I973 SHEETEUFI H Y b PATENTEI]SEPZS I975 SHEET 30F 4 V PATENTED SEP2 5 I973 SHEET U 0F 4 l METHOD ANDAPPARATUS FOR SNOW MAKING This invention relates to a method andapparatus for making snow as commonly produced by snow-making equipmentnow in use in providing a cover of snow on winter recreational areassuch as ski slopes and the like.

In conventional snow-making methods, limitations are present, both withrespect to the amount of snow which can be produced in any given timeinterval, as well as the characteristics or quality of the snowparticles which are made and spread over a ski slope surface.

As is well known, temperature of ambient air, where snow-making is to becarried out, must be in the freezing range, and preferably should be ina range of 28 F. and lower. We have determined that the eflectiveness ofthe ambient atmosphere in converting an expanded mixture of air andwater into snow particles may de pend to some extent in the way in whichthe cold ambient air occurring in the immediate vicinity of the regionof expansion is utilized. We have observed that if too great a demandfor cold air occurs, efficiency in snowmaking may drop appreciably. Thisis evidenced by the fact that relatively large flows of air and watermixtures in the terms of cubic feet per minute may not do assatisfactory a job of snow-making as a plurality of snow makers usingrelatively smaller flows of the mixture. We have also determined thatanother highly important factor is the snow particle condition or flakecharacteristics which are created by the snow-making process. Forexample, a wet, heavy form of snow particle is less desirable since itdoes not spread properly andmay accumulate in objectionable piles. n theother hand, if the snow flakes or cyrstals are too fine, theymay, whenbeing producd in a windy area especially, be blown away or fail to coverproperly with a satisfactory accumulation being realized in a desiredportion of a ski slope.

It is a chief object of the invention, therefore, to provide an improvedsnow-making method and apparatus which is characterized especially bysubstantially greater efficiency than is obtainable with conventionalsnow-making equipment.

Another object of the invention is to increase the rate at which snowcan be made in any given suitably cold ambient air atmosphere and toprovide an improved snow-making jet construction suitable for thispurpose.

Another object of the invention is to devise a method of precoolingstreams of compressed air and pressurized water to obtain greaterefficiency in snow-making and to make possible the production of a snowcover at temperatures higher than those customarily relied upon for asuccessful snow-making operation.

Still another object is tocontrol more efiectively the characteristicsof the snow flakes or snow cyrstals which are formed in a snow-makingprocess.

Still another object is to devise an apparatus in which precooling ofcompressed air and water may be carried out in a novel manner.

And still another object is to devise an improved method of utilizingcold ambient air in a localized re gion of snow-making.

The nature of the invention and its other objects and novel featureswill be more fully understood and appreciated from the followingdescription of a preferred emboidment of the invention selected forpurposes of illustration and shown in the accompanying drawings, inwhich:

FIG. 1 is a perspective view illustrating one preferred embodiment ofsnow-making apparatus of the invention;

FIG. 2 is a fragmentary plan view illustrating a nozzle section andsupply conduit means;

FIG. 3 is a crosssection taken on the line 3-3 of FIG. 2;

FIG. 4 is a cross section taken on the line 44 of FIG. 3;

FIG. 5 is a cross section taken on the line 5-5 of FIG. 3;

FIG. 6 is a cross section taken on the line 6-6 of FIG. 3;

FIG. 7 is a detail elevational view of a conduit portion of thesnow-making apparatus of the invention with one of the nozzles removedtherefrom;

FIG. 8 is a fragmentary elevational view further illustrating details ofa conduit portion for the snow-making apparatus of the invention andspecial valve mechanism combined therewith.

With the foregoing objectives in view, we have conceived of an improvedmethod for making snow wherein high velocity streams of compressed airand pressurized water are furnished in a cold ambient atmo sphere fromtwo or more independent sources of supply and the streams of air andwater are precooled in a special a jet structure before being mixed anddis charged from nozzle means at the outer end of the jet structure.

Our improved method is devised to operate upon the principle of moreefficiently utilizing the cold ambient atmosphere occurring in alocalized area in which snow-making is desired to be carried out at anygiven period. Essentially, our improved method of operation is based onthe idea of using cold ambient atmosphere to lower the temperature ofstreams of compressed air and water while separated and in a confinedstate ina snow-making jet structure. By means of precolling inthisrnanner and in other ways hereinafter noted, we

1 find that subsequent cooling realized from conven- 'tional expansionof the mixture in the cold ambient atmosphere results in a materiallyimproved method of making snow.

In our improved method, one desirable form of precooling may, forexample, be carried out by momentarily confining the high velocitystreams in isolated relationship and in elongated restricted passagewaysformed in a special jet structure which is exposed at its outer surfaceto cold ambient atmosphere.

Portions of the passageways may be arranged in concentric relationshipso that an inner stream of compressed air undergoes peripheralprecooling by means of an outer cold stream of pressurized water whichin turn is cooled by cold ambient atmosphere in which the conduit meansis positioned.

We have also determined that important precooling may be accomplished bysuch steps as introducing controlled quantities of precooled air intothe stream of water and by carrying out partial expansion of the mixturein a confined space in the nozzle section of the jet structure. Theresulting precooled mixture may then be discharged through the nozzlemeans into a a cold ambient atmosphere to accomplish a final expansionof the mixture and formation of snow at efficiency levels not heretoforerealized in the art of snow-making.

Referring to the drawings, the snow-making apparatus shown thereincomprises one preferred embodiment of means for carrying out theinvention method. It will be understood, howvever, that the invention isnot intended to be limited to this apparatus and it may be desired tocarry out the method in other ways.

In general, the apparatus employed includes a snowmaking jet structuregenerally indicated by the arrow J, and means for furnishingindependently supplied streams of compressed air and pressurized water,utilizing conventional air compressor and water pumping equipment whichis not shown in the drawings, but is indicated in the form of compressedair and water pipes A and W respectively, as shown at the right handside of FIG. 1.

In the preferred embodiment shown in FIG. 1, there is also illustrated ajet supporting tower member T mounted on a movable base B forlocatingthe jet structure at any desired height above an area to be covered withsnow. It may also be desired to utilize the jet structure of theinvention indendently of the tower, and for this purpose a conventionalsled or bracket structure may be utilized.

Considering in greater detail the jet structure J, components of whichare indicated in FIGS. 2 to 8, inclusive, numeral 2 denotes an elongatedenclosure body of generally tubular form having a handle part II. Thisenclosure body constitutes a basic component of our improved snow jetconstruction and consists in a multipassageway conduit designed toconduct flows of compressed air and water and function as a novel meansof precooling the flows. We have found that by using suitable dimensionsfor the length of the enclosure body as well as the size of thepassageways, it becomes possible to carry out significant precooling ofthe fluids. In a typical snow jet construction of the invention, thelength of the overall enclosure body may be, for example, approximatelysix inches, and the air passageway may be of a diameter of, for example.I and inches, and the diameter of the annular passageway for watercontained within an outer water jacket portion of the enclosure body maybe, for example, of 3 and Pi inches.

In furnishing fluid flows through this elongated enclosure body 2, weprovide at one end, a threaded connection 4 which is designed to haveconnected thereto the air pipe A. Communicating with this threadedconnec-- tion 4 is an elongated air conducting passageway 6 whichextends all the way through the enclosure body 2, as is most clearlyshown in FIGS. 3 and 4.

In accordance with the invention, we further form the enclosure body 2with an inner tubular section 8 which is supported in spaced relation tothe outer tubular portion of the enclosure body 2 by means of a web 10.There is thus defined an outer annular water conducting passageway 12which is concentrically arranged with respect to the air passagewaythroughout a part of the length of passageway 6, and outer portions ofenclosure body 2 function as a water jacket section.

Formed integrally with enclosure body 2 at a lower side thereof,immediately below the passageway 6, is a water conduit portion 14through which extends a water passageway 16, as best shown in FIG. 3.The water passageway 16, as also indicated in FIG. 3, is incommunication with the water passageway 12 at a point of mergingoccurring directly below the handle portion H.

It will be observed that by means of the concentrically spaced tubularconstruction described, the passageways 6 and 12 are located incircumferentially spaced apart relationship and thus a flow of water inthe passageway 12 completely surrounds a flow of air passing through thepassageway 6 for a substantial distance of travel. Attention is directedto the fact that when the relatively thin outer water jacket portion ofenclosure body 2 being exposed to a cold ambient atmosphere, cooling ofwater passing therethrough may be realized. It is pointed out thatcompressed air flowing inside of the relatively thin tubular portion 8can derive a cooling effect from the surrounding body of relativelycolder water.

In combination with this cooling structure made up of concentricallyarranged tubular parts, as noted above, we may further construct theenclosure body 2 with a manifold supporting housing end 20. The housingpart 20 is formed at two opposite sides with flat retaining surfacesagainst which are detachably secured a pair of manifold members M1 andM2 bymeans of fastenings 22, 24, etc., as shown in FIGS. 1 and 2.Supported at outer extremities of the manifold members M1 and M2 arespaced nozzle members N1 and N2 which are of hollow construction toprovide mixing chambers 28 and 30 terminating in restricted orifices 28aand 30a.

An important feature of the invention consists in the provision of ductmeans for carrying out a further stage of precooling of the water andthe compressed air. The duct means includes separated air and wateroutlets which are formed in opposite sides of the housing body 20 toguide air and water in isolated relationship to one another away fromthe passageways 6 and 12 and intthe manifold members M1 and M2. Asshown, for example in FIGS. 3, 4 and 8, a transversely located opening32 is formed in the housing to intersect at right angles the passageway6, thus forming dual opposite outlets for the air. Likewise, theadjacent portions of the housing 20 are formed with transversely locatedapertures 34, 36, 38 and 40. These apertures are most clearly indi-,

cated in FIGS. 4 and 8 and occur on two opposite sides of the passageway32.

Each of the manifold members M1 and M2 are formed with complementaryflat faces through which extend openings corresponding to those in thehousing 20. Thus, as shown in FIG. 7 the manifold face Ml is formed withan air opening 32 and water apertures 34' and 38' so that when themanifold is secured in place, a continuous passageway is realized, asshown in FIG. 4.

Extending away from the openings in faces of each of the manifolds areduct portions D1 and D2 which terminate in restricted tip portions D3and D4 having openings D5 and D6. The ducts D1 and D2 are supported inspaced relation to the wall sections of the manifolds M1 and M2, asshown in FIG. 4, and this arrangement provides for water leaving thepassageway 12 to pass through the manifold and around the duct portionsD1 and D2 and their tips D3 and D4 to mix with compressed air leavingthe orifices D5 and D6.

By means of this arrangement of parts, a further stage of cooling can berealized both by reason of cold water circulating around the ductmembers D1 and D2 and also by reason of the fact that some expansion ofthe compressed air occurs as the air leaves the orifices D5 and D6 justprior to being mixed with water and ejected through the orifices 28a and30a into the outer atmosphere where still another stage of cooling takesplace.

It is pointed out that the stages of cooling accomplished by the methodand apparatus described results in both the water and the air reachingthe outer ambient atmosphere at an appreciable lowered temperature, withthe result that the outer ambient air can operate more effectively inproducing snow.

We have also determined that we can very desirably control thecharacteristics of the snow which is produced by the method describedthrough the aid of a special valve mechanism V illustrated in FIGS. 1, 23, 5 and 8. As noted in FIGS. 3 and 5, we form the inner tubular section8 with a valve aperture V1 by means of which compressed air confined inthe tubular member 8 may be released into the space enclosed by thetubular section 2. Arranged to move into and out of sealing relationwith a valve seat formed around this opening V1 is a valve head V2 whichis rotatably supported in a threaded connection V3 in the enclosure body2. A hand wheel V4 provides for adjusting the valve head V2 as desired.We have found that by precooling air in the passageway 6, and thenallowing this precooled air to become injected in small quantities intoa surrounding flow of water, there is accomplished a seeding of watercrystals in the water and the quality of the snow particles ultimatelyproduced in the ambient atmosphere outside the orifices 28a and 30a isregulated in size and wetness so that improved snow covering action canbe realized and a more uniform distribution of snow can be accomplished.

As earlier pointed out, the invention, although not limited thereto, maybe combined with a tower member T to accomplish a reverse precoolingaction to that which takes place in the enclosure body 2. This isaccomplished by introducing air through the passageway A into theinterior of the tower T, as shown in FIG. 1, so that this air with theturret surface being exposed to a cold ambient atmosphere undergores adegree of precooling. At the same time, water furnished through the pipeW is conducted through the tower T inside of this flow of precooled airuntil reaching an outlet port W1; similarly the air exits an outlet portAl. From these outlet ports, Al and W1, the flows are reversed andconducted into the enclosure body 2 so that the air is located inside ofthe water to accomplish the precooling described.

From the foregoing description, it would seem that we have disclosed animproved method of making snow, and we have found that by means of theprecooling stages described, we are enabled to operate at sometemperature levels in the freezing range which are not normally feasilbefor conventional snow making. More importantly, we have found that byutilizing the precooling stages described, either in one form oranother, it becomes possible, with relatively small snow-making units,to increase snow production as much as two or three times over thatwhich can be reailized with conventional snow-making equipment. The jetstructure described is compact and readily movable about a ski slope andrequires a minimum amount of attention and handling by snow-makingoperators.

We claim:

1. In a method of snow-making, the steps which in clude furnishingstreams of compressed air and pressurized water from two independentsources of supply, conducting the streams into an enclosure body inwhich precooling takes place and ejecting a mixture of the compressedair and water into a cold ambient atmosphere in which the mixtureundergoes expansion and further cooling to produce snow particles, saidprecooling being carried out in successive stages including a firststage in which precooling is carried out by exposure to cold ambientatmosphere to lower the temperature of the said compressed air, a secondstate in which controlled amounts of the lowered temperature air isinjected into the water while confined in the enclosure body, and athird stage in which portions of the lowered temperature air undergoesexpansion and additional cooling while contained in the enclosure body.

2. In a method of snow-making, the steps which include furnishingstreams of compressed air and pressurized water from two indendentsources of supply, conducting the streams into an enclosure body inwhich precooling takes place and ejecting a mixture of the compressedair and water into a cold ambient atmosphere in which the mixtureundergoes expansion and further cooling to produce snow particles, saidstep of furnishing the streams of compressed air and water includingleading the streams through independent cooling chambers in whice theinner cooling chamber conducts the water and an outer cooling chamberconducts the air, with the outer cooling chamber having a surfaceexposed to the cold ambient atmosphere.

3. A method of making snow in which a mixture of compressed air andwater is ejected from a snowmaking nozzle and expanded and cooled in acold ambient atmosphere to form snow particles, the steps which includeconfining the high velocity streams of compressed air and water in anelongated enclosure body which is exposed to the cold ambient atmosphereand lowering the temperature of the confined streams of air and waterwhile in isolated relationship, then injecting metered quantities of therelatively lower temperature air into the relatively higher temperaturewater, and thereafter ejecting a mixture of the air and airinjectedwater into the cold ambient atmosphere to form snow particles whoseparticle characteristics are controlled by the said injection of theinternally injected air.

1. In a method of snow-making, the steps which include furnishingstreams of compressed air and pressurized water from two independentsources of supply, conducting the streams into an enclosure body inwhich precooling takes place and ejecting a mixture of the compressedair and water into a cold ambient atmosphere in which the mixtureundergoes expansion and further cooling to produce snow particles, saidprecooling being carried out in successive stages including a firststage in which precooling is carried out by exposure to cold ambientatmosphere to lower the temperature of the said compressed air, a secondstate in which controlled amounts of the lowered temperature air isinjected into the water while confined in the enclosure body, and athird stage in which portions of the lowered temperature air undergoesexpansion and additional cooling while contained in the enclosure body.2. In a method of snow-making, the steps which include furnishingstreams of compressed air and pressurized water from two indendentsources of supply, conducting the streams into an enclosure body inwhich precooling takes place and ejecting a mixture of the compressedair and water into a cold ambient atmosphere in which the mixtureundergoes expansion and further cooling to produce snow particles, saidstep of furnishing the streams of compressed air and water includingleading the streams through independent cooling chambers in whice theinner cooling chamber conducts the water and an outer cooling chamberconducts the air, with the outer Cooling chamber having a surfaceexposed to the cold ambient atmosphere.
 3. A method of making snow inwhich a mixture of compressed air and water is ejected from asnow-making nozzle and expanded and cooled in a cold ambient atmosphereto form snow particles, the steps which include confining the highvelocity streams of compressed air and water in an elongated enclosurebody which is exposed to the cold ambient atmosphere and lowering thetemperature of the confined streams of air and water while in isolatedrelationship, then injecting metered quantities of the relatively lowertemperature air into the relatively higher temperature water, andthereafter ejecting a mixture of the air and air-injected water into thecold ambient atmosphere to form snow particles whose particlecharacteristics are controlled by the said injection of the internallyinjected air.